One power stroke thruster with locking cartridge case



May 10, 1960 w, KRQEGER ET AL 2,935,911

ONE POWER STROKE THRUSTEIR WITH LOCKING CARTRIDGE CASE Filed Feb. 15, 1957 INVENTOR. WILLIAM J. KRCEGER By SYLVAN D. ROLLE I} 4% xm-%4.M

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nt-a United States Patent ONE POWER STROKE THRUSTER WITH LOCKING CARTRIDGE CASE William J. Kroeger and Sylvan D. Roll, Philadelphia, Pa. Application February 15, 1957, Serial No. 640,562

y 2 Claims. c1. 89-1) I 1 (Granted the. Title 35, us. Code 1952 sec. 266) The invention described herein-may be manufactured and'used by or for the Government for governmental purposes without payment of any'royaltyther'e'on. V

This invention relates to a cartridge actuated device of the type known as thrusters, catapults and the like. An object is to provide a device of this class having a simplified construction which is better able to withstand shocks in handling and installing. Another object is to provide a device in which the propellant system is hermetically sive topressure within the cartridge case for unlocking it. More specifically, a cartridge case is provided with a frangible wall portion between the lower end connected to an outer casing and an upper portion which holds the power applying element against outward, motion until after the attainment of a predetermined pressure in the cartridge case when its upper portion ruptures.

Referring to the drawing, Fig. 1 shows a longitudinal section of the lower end portion of one embodiment of this invention.

. Fig. 2 is a view of a modification in which the lower end of the cartridge case is similar to that of Fig. 1 but in which a different upper end is provided for the cartridge case.

In Fig. 1 of the drawing an outer casing or tube 10 is V T, shown on the outside of an intermediate tube 11 which has provided radially within it an inner tube 12. A cartridge casehas a side wall 13 and a lower end portion provided with a rim 14 such as is customary for extraction of a spent cartridge case. A metal base ring 15 is provided with a threaded connection 16 to the outer tube 10. A

' flange 17 on the base ring extends over the flange 14 of the cartridge case so that it is impossible for the cartridge i'case to be moved upwardly. The cartridge case'13 is provided with a roof 18 of substantial strength as will be herein'after' pointed out. A flange 19 is provided on the upper endportion of the cartridge case extending radially f outward far enough to extend over the split ring 20. This expansible ring 20 rests on a ledge 21 formed in the inner tube 12. In this Way, the flange 19 on the cartridge case holds the inner tube 12 against upward move- .ment prior to firing of the cartridge.

Intermediate, the longitudinal ends of the cartridge case, one or more inner circumferential recesses 22 are provided to reduce the effective wall thickness so that on firing, the pressure generated within the cartridge case causes one of these weakened wall portions to rupture. Beneath the flange 14 g is provided a breech closure not shown in order that the 7 2,935,911 Patented May 10, 1 960 ent invention in which the lower end of the thruster orv catapult and the lower ends of the cartridge case are the same as is shown in Fig. 1 but the upperend of the'care tridge case is slightly different inthat a locking ring 23 is threaded to the upper end portion of] the cartridge case 24 instead of having a flange 19 to project over-"the ring 23. In Fig. 2 parts similar to those in Fig. 1are designated by the same reference numerals with letter a attached. p

In assembly of the device shown in Fig. 1 the inner tube 12 having a closed upper end is usually provided with the split ring 20 inserted within the ledge 21 before 'the cartridge case 13 is put in place. This ring 20 is also preferably of the type such that it is fixedneither tightly against the inner Wall surface of the inner tube nor does it in tightly against the outer surface of the cartridge case, but

instead rests upon the ledge somewhere between these two extreme divisions. When the ring 20 is put in place the cartridge case may also be inserted at the same time with the ring 20 under the flange 19 and it will be understood that the flange 19 does not extend radially outward 'far enough to preclude the cartridge case and the ring being inserted from the lower end portion into the inner tube. In Fig. 2, the ring 23 is preferably inserted into the lower end of the inner tube before the cartridge case is inserted and then after the ring 23 has been inserted the cartridge case may then be threaded into the ring 23.

On firing the cartridge in Fig. 1 gas pressure generated within the cartridge case acts to raise the roof 18 imposing tensional stress to side walls 13. But inasmuch as the lower flange 14 precludes the cartridge case moving'upwardiy, the base ring 15 being connected tothe outer tube 10 acts to anchor the lower ends of the cartridge case to the outer walls. However, when the gas pressure within the cartridge case reaches the predetermined value, one of the wall portions of reduced thickness ruptures allowing the upper end of the cartridge case to rise to the height of the closed upper end of the inner tube 12.

Among the advantages of the present invention may be mentioned the fact that it provides a simple and inexpensive construction for locking the thruster or catapult against premature movement. This type of construction is adapted for embodiment in existing catapults with comparatively little effort and expense. The pressure is gen:

erated within the cartridge case and causes the cartridge case to be ruptured before pressure enters the thruster or catapult. V

As used hereinafter, the term thruster includes a catapult and any other cartridge actuated device having two or more sections such as a cylinder and cylinder with a piston and piston rod.

We claim: 7 1.. In a multi-tube thruster having an outer casing, a base ring secured thereto, an inner tube, at least one intermediate tu-be, and a cartridge case located within, a lower portion of said inner tube for containing propellant for actuating said thruster, the combination therewith of the improvement for simplifying a lock between the inner tube and outer casing and better enabling it to withstand shocks incident to handling and installing, said improvement in- 7' cluding said base ring being provided with a central opening axially therein, a radially inwardly extending flange within said base ring opening above a lower face of said base ring, a radially outwardly extending rim flange on said cartridge case contiguous to said base ring flange on a lower and outer side of said base ring flange, said cartridge case having a closed inner end and being fran-' gible to propellant pressure therein, said inner tube'having a ledge formed on an inner wall surface, and a ring plunger or a :f

seated on said ledge, a flange adjacent the closed inner end of said cartridge case extending radially outward over said ring, whereby said cartridge case is held against downward movement and said inner tube is held against upward movement with respect to said cartridge case, base ring, and outer casing, said cartridge case having cylindrical side walls with an intermediate portion thereof circumferentially scored to localize the portion of the cartridge case to be ruptured under stress of propellant ignition pressure.

2. In a multi-tube thruster having an outer casing, a base ring secured thereto, an inner tube, at least one intermediate tube, and a cartridge case located within a lower portion of said inner tube for containing propellant for actuating said thruster, the combination therewith of. the improvement for simplifying a lock between the inner tube. and outer casing and better enabling it to withstand shocks incident to handling and, installing, said improvement including said base ring being provided with a central opening axially therein, a radially inwardly extending flange within said base ring opening above a lower face of said base ring, a radially outwardly extending rim flange on said cartridge case contiguous to said base ring flange on a lower and outer side of said base ring flange, said cartridge case having a closed inner end with cylindrical side walls having an intermediate portion circumferentially scored to localize the frangible portion to be ruptured under ignition of propellant, said inner tube having a ledge formed on an inner wall surface, a ring seated on said ledge, and a threaded connection between said ring and cartridge case, whereby said cartridge case is held against downward movement and said inner tube is held against upward movement with respect to said cartridge case, base ring, and outer casing.

References Cited in the file of this patent UNITED STATES PATENTS 

